A survey of total IgE reference intervals reported by Scandinavian and British medical laboratories - a need for harmonisation.

OBJECTIVES: There appears to be marked discrepancies between total IgE reference intervals (RIs) in use by many laboratories and those recommended by published studies. The aim of this study was therefore to review total IgE RIs currently reported by Scandinavian and British laboratories and to compare these to published RIs identified by a literature review. METHODS: Relevant laboratories were identified by test directories provided by the national accreditation bodies in Norway, Sweden, Denmark and the UK. Total IgE RIs and their sources were acquired by accessing laboratory user handbooks or by an electronic survey. In addition a literature review of published total IgE RI studies was performed. RESULTS: From 172 accredited laboratories providing total IgE analysis, data was acquired from 122 laboratories. An adult upper reference limit between 81 to 150 kU/L was reported by 89% of these. Denmark and Sweden reported the most harmonised RIs whilst Norway and the UK exhibited the least degree of harmonisation. Published adult (n = 6) and paediatric (n = 6) RI studies reported markedly higher upper limits than those currently in use by the laboratories included in this study. There were also large variations in the number of age strata in use for paediatric RIs. CONCLUSION: This study demonstrates large variations in currently utilised IgE RIs by Scandinavian and British accredited laboratories and most report markedly lower RIs than those recommended by recent RI publications. Many laboratories likely utilise outdated RIs and should consider critically reviewing and updating their RIs.

Diet, Food, and Nutritional Exposures and Inflammatory Bowel Disease or Progression of Disease: an Umbrella Review.

Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), contributes to substantial morbidity. Understanding the intricate interplay between dietary factors and the incidence and progression of IBD is essential for developing effective preventative and therapeutic strategies. This umbrella review comprehensively synthesizes evidence from systematic reviews and meta-analyses to evaluate these complex associations. Dietary factors associated with an increased incidence and/or progression of IBD include a high intake of red and processed meat, other processed foods, and refined sugars, together with a low intake of vegetables, fruits, and fiber. For most other food groups, the results are mixed or indicate no clear associations with IBD, CD, and UC. Some differences seem to exist between UC and CD and their risk factors, with increased intake of dietary fiber being inversely associated with CD incidence but not clearly associated with UC. Dietary fiber may contribute to maintaining the gut epithelial barrier and reduce inflammation, often through interactions with the gut microbiota. This seems to play an important role in inflammatory mechanisms in the gut and in IBD incidence and progression. Diets low in fermentable saccharides and polyols can alleviate symptom burden, but there are concerns regarding their impact on the gut microbiota and their nutritional adequacy. Mediterranean diets, vegetarian diets, and a diet low in grains, sugars, and lactose (specific carbohydrate diet) are also associated with lower incidence and/or progression of IBD. The associations of dietary patterns are mirrored by inflammatory biomarkers. IBD is typically treated pharmaceutically; however, many patients have a suboptimal response to medical treatments. The findings from this umbrella review could provide evidence for nutritional counseling and be a valuable addition to traditional treatment plans for IBD. This systematic review was registered at PROSPERO as CRD440252.

Prevalence of left ventricular hypertrophy in children and young people with primary hypertension: Meta-analysis and meta-regression.

Background: Left ventricular hypertrophy (LVH) is the main marker of HMOD in children and young people (CYP). We aimed to assess the prevalence of LVH and its determinants in CYP with primary hypertension (PH). Methods: A meta-analysis of prevalence was performed. A literature search of articles reporting LVH in CYP with PH was conducted in Medline, Embase, and Cochrane databases. Studies with a primary focus on CYP (up to 21 years) with PH were included. Meta-regression was used to analyze factors explaining observed heterogeneity. Results: The search yielded a total of 2,200 articles, 153 of those underwent full-text review, and 47 reports were included. The reports evaluated 51 study cohorts including 5,622 individuals, 73% male subjects, and a mean age of 13.6 years. LVH was defined as left ventricle mass index (LVMI) ≥ 95th percentile in 22 (47%), fixed cut-off ≥38.6 g/m2.7 in eight (17%), sex-specific fixed cut-off values in six (13%), and miscellaneously in others. The overall prevalence of LVH was 30.5% (95% CI 27.2-33.9), while heterogeneity was high (I 2 = 84%). Subgroup analysis including 1,393 individuals (76% male subjects, mean age 14.7 years) from pediatric hypertension specialty clinics and LVH defined as LVMI ≥95th percentile only (19 study cohorts from 18 studies), reported prevalence of LVH at 29.9% (95% CI 23.9 to 36.3), and high heterogeneity (I 2 = 84%). Two studies involving patients identified through community screening (n = 1,234) reported lower LVH prevalence (21.5%). In the meta-regression, only body mass index (BMI) z-score was significantly associated with LVH prevalence (estimate 0.23, 95% CI 0.08-0.39, p = 0.004) and accounted for 41% of observed heterogeneity, but not age, male percentage, BMI, or waist circumference z-score. The predominant LVH phenotype was eccentric LVH in patients from specialty clinics (prevalence of 22% in seven studies with 779 participants) and one community screening study reported the predominance of concentric LVH (12%). Conclusion: Left ventricular hypertrophy is evident in at least one-fifth of children and young adults with PH and in nearly a third of those referred to specialty clinics with a predominant eccentric LVH pattern in the latter. Increased BMI is the most significant risk association for LVH in hypertensive youth.